A conventional remote maintenance system is known as an information processing system having the function of notifying a fault that has occurred in the user device to the maintenance center device, in which upon detection of a fault of the user device, the fault information is notified to the maintenance center device by electronic mail (email) through a network, such as the Internet and the maintenance center device diagnoses the environment of the user device based on the email transmission thereby providing the proper maintenance service.
In this conventional remote maintenance system, the monitor agent is packaged in the user device as software for monitoring a hardware fault of the user device, and upon detection of a fault of the user device, transmits the fault occurrence to the maintenance center device at a remote place by email through a network, such as the Internet. The maintenance center device diagnoses the user device based on the email transmission, and based on the result of this diagnosis, notifies support personnel that the fault notice-has been received from the user device. The support personnel who has received the fault notice confirms the content of the fault notice and travels to repair the user device with the required replacement parts, thereby making it possible to provide the proper maintenance service.
The maintenance center device is required to be supplied with not only the information notifying a fault, but also various other information including the log information required for the fault investigation to specify the faulty part and the fault point of the user device, the information on the software and hardware configuration and the information on the environment of the user device. The information (hereinafter referred to as the attached file) is so large in size (generally, several hundred kilobytes (KB) to several megabytes (MB)) that the size of the transmission of the email is limited depending on the email transmission environment of the user (for example, the tolerable maximum capacity of the email used by the user is set at 10 megabytes). In order to not exceed this size limit, therefore, the monitor agent of the user device is generally required to divide the attached file to generate a plurality of divided files and carry out the mail transmission in a plurality of divided emails with the divided files attached thereto. In the process, the attached file is compressed to minimize the size thereof, and further, in order to prevent the leakage of the information exclusive to the user, encrypted before being divided.
In the maintenance center device, a plurality of divided emails transmitted from the monitor agent are received separately from each other, and when all of the divided emails are collected, combined with each other and after decryption and decompression, the original file is retrieved.
This conventional division email transmission method for the remote maintenance system; however, poses problems (1) and (2) described below.
(1) A part of the plurality of the division emails may fail to reach the maintenance center device due to a fault in the network.
(A) With the size reduction of each division email and the resultant increase in the number of the division emails, a part of the divided emails may be lost with a higher probability.
(B) In accordance with the RFC (Request for Comments; documents for standards edited by IETF (Internet Engineering Task Force)) agreement, information such as “Content-Type: message/partial” (indicating that a particular email is a part of the plurality of divided mails) is normally added to the email header of each of a plurality of divided emails. Since each division email constitutes only a part of the attached file, virus scan cannot be performed. As a result, the transmission of the divided emails (with the information such as “Content-Type: message/partial” added thereto) is sometimes rejected or the attached file of the divided email may be replaced with a warning text in the antivirus gateway (GW) introduced into the customer environment, with the result that a part of the plurality of the divided emails may fail to reach the maintenance center device or, in spite of the arrival of a part of the divided emails, the original attached file often cannot be restored.
According to a method conceived to avoid the aforementioned problem, a plurality of divided emails are generated by dividing the attached file without using the information such as the message/partial stipulated by RFC against the divided emails. In this method, the plurality of the divided emails are not treated as divided emails by the antivirus gateway, and therefore, checked for a virus and spam (i.e., junk mail or the like sent at random without regard to the intention of the receiver) check in the normal way. In this case, however, each divided email, compressed and encrypted, is binary data. Therefore, a character string which is to be formed in the binary data may be erroneously recognized as a virus or spam, with the result that the divided email may be rejected by the antivirus gateway.
(2) In the remote maintenance system, it is important to quickly judge whether the divided email sent thereto is the information on a fault of the user device or the simple information on other than a fault (for example, the information on the hardware or software configuration, etc.), and in the case where the email concerns the fault information, to take an appropriate action immediately. Before the arrival of the plurality of divided emails, however, the original attached file cannot be retrieved, and therefore, the content of a fault developed in the user device or the user device constituting a fault source cannot be identified. Thus, the degree of emergency cannot be determined for the information sent thereto.
Patent Documents 1 to 3 relating to the divided email transmission method for the conventional remote maintenance system are described below for reference.
Patent Document 1 discloses a technique for information transmission method through a computer network, in which the information to be transmitted is divided into a plurality of pieces, and by attaching header information including identification information indicating the association with the same group and the serial number indicating the order to each of the pieces of information, is transmitted by email.
The technique disclosed in Patent Document 1, however, is nothing but the description of the process of transmitting each of the plurality of divided information by adding thereto the identification information indicating the association with the same group and the serial number indicating the order of transmission, and fails to refer to the transmission of each division information by adding thereto the header information indicating the content of the fault occurrence notice. According to the technique disclosed in Patent Document 1, therefore, the original information transmitted cannot be retrieved before arrival of the plurality of divided information, so that neither the content of a fault in the original information transmitted nor the degree of emergency of the transmitted information can be determined at the time point when any one of the plurality of the divided information is received.
Patent Document 2, on the other hand, discloses a technique for an image transmission method in which the image data read by the scanner is divided into a plurality of image data, and by adding the email header indicating the position of each divided file to a plurality of divided files thus obtained, each divided file is sequentially transmitted by email.
Patent Document 2, however, describes only the process of transmitting each divided file by adding the email header indicating the position of each division file to each of the plurality of the division files, and fails to refer to the transmission of each divided file by adding thereto the header information indicating the content of the fault occurrence notice. According to the technique disclosed in Patent Document 2, the original image data cannot be retrieved before arrival of the plurality of the divided files, and therefore, the content of the fault of the original image cannot be identified when any one of the plurality of the divided files is received.
Patent Document 3 discloses a technique for the remote maintenance system in which upon detection of a fault in the user device by a monitor agent packaged in the user device, the attached file containing the fault information is divided into a plurality of data after being compressed and encrypted, and the resulting plurality of division data are transmitted by email to the maintenance center device. The maintenance center device, in turn, diagnoses the email transmission environment of the user device and transmits the diagnosis result to the user device by email.
Patent Document 3, however, describes only a configuration in which the attached file containing the fault information is divided into a plurality of divided data after compression and encryption, followed by transmission of each division, and fails to refer to the addition of the header information indicating the content of the fault notice to each division data. According to the technique disclosed in Patent Document 3, like those disclosed in Patent Documents 1 and 2, therefore, the original attached file cannot be retrieved before arrival of the plurality of the divided data. Therefore, the content of a fault developed in the user device, etc., and the degree of emergency of the attached file cannot be determined when any one of the plurality of the divided data is received.
In other words, none of the techniques disclosed in Patent Documents 1 to 3 can solve the problem encountered by the conventional divided mail transmission method.
Patent Document 1: Japanese Unexamined Patent Publication No. 11-163937
Patent Document 2: Japanese Unexamined Patent Publication No. 2002-288097
Patent Document 3: Japanese Unexamined Patent Publication No. 2007-108977